At the cathode the metal ions are being oxidized through the loss of one or more electrons.

At the anode:

Br + 1 e^-1 = Br^-1

O + 2 e^-1 = O^-2

F + 1 e^-1 = F^-1

At the anode, the non-metal ions are being reduced by the gain of one or more electrons.

These are examples of half-cell reactions. If you are doing an oxidation-reduction reaction the loss of electrons at one electrode has to equal the gain of electrons at the other electrode. The metals are reducing agents and the non-metals are oxidizing agents.

To remember this: "an oxidizing agent is reduced by the gain of electrons"